So yes, to get on to a PhD it's slightly better to have a MRes (same as MSc by Reseach), if the two masters were very similar. If you have a very subject-relevant MSc, then that may be better than a MRes in a less relevant subject area.
But really, I actually don't think it matters that much for a PhD application. The interview is far more important - where they are going to be assessing you on ability to learn, resilience, enthusiasm, likeability and how you will fit in with the PhD group.
If there are exceptional candidates, maybe the choice of masters comes into play, but I don't think it's the most important factor in the majority of cases.